延长冷挤压凸模使用寿命的研究

W6Mo5Cr4V2钢冷挤压凸模,应用1200℃淬火、560℃回火三次,磨削加工,软氮化和滚压的复合强化工艺,可以改善其表面凹凸状况,产生较大的残余压应力,使其寿命得到大幅度提高。     

Prenatal diagnosis and postnatal follow-up of a child with two de novo unrelated balanced reciprocal translocations

Two unrelated, apparently balanced, reciprocal translocations involving chromosomes 3 and 17, and 10 and 15 were found in cultured amniotic fluid cells from a 41-year-old 10-gravida. Chromosome analysis of peripheral blood lymphocytes of both parents revealed normal katryotypes. Post-partum examination of lymphocyte cultures from the proband confirmed the chromosome rearrangements. The child showed normal development during follow-up examinations up to the age of 4 years.     

环境水样中痕量Fe3+的测定方法研究

在酸性介质中(pH 5.0),Fe3+能与硫氰酸盐生成稳定的配离子[Fe(SCN)6]3-,该配阴离子能与碱性717型阴离子交换树脂定量交换缔合,形成阴离子交换树脂(R+)--金属离子(Mn+)--硫氰酸盐(SCN-)三元配合缔合体系,其最大吸收波长分别为490 μm,与二元水相最大吸收波长相同,通过制作薄层测定了水中Fe3+含量.本法具有较高的灵敏度ε630Fe3+=2.4×105 L·mol-1·cm-1,测定0.6 μgFe3+6次,RSD=2.7%,实测了水样中,Fe3+含量并与AAS法测定结果比较,Fe3+测定的线性范围0～10 μg/25mL,体系检出限为0.12 μmol/L.     

凹凸棒土复合净水剂处理印染废水

用活化后的凹凸棒粘土配制成复合净水剂处理印染废水，色度去除率达９３％以上，ＣＯＤ去除率达７４％，每立方米废水处理费用约０．１５元，压滤渣可用于制砖。     

Performance of various sub-grid scale models in large-eddy simulations of turbulent flow over complex terrain

Turbulent flow over a two-dimensional steep hill was analyzed by large-eddy simulations (LES). Here, six LES computations were carried out using four different sub-grid scale (SGS) models and two different ground surface conditions. The accuracy of these computations was assessed by comparing the results with those from an experiment by Ishihara et al. (An experimental study of turbulent boundary layer over a steep hill, Proceedings of the 15th National Symposium on Wind Engineering, 1998, pp. 61–66; J. Wind Eng. 89 (2001) 573). The results of the dynamic SGS models were in very poor agreement with those of the experiment. The poor prediction accuracy was mainly caused by the inaccurate estimation of the model coefficient near the ground surface. In order to improve the prediction accuracy of the dynamic SGS models, a hybrid SGS model, i.e., a combination of the standard Smagorinsky model and the dynamic Smagorinsky model, was introduced. The hybrid model provided very accurate predictions and produced the best results of the four SGS models compared here.     

络合物吸附波法测定废水中微量铜

本文介绍了Cu-CNS-HSCH_2COOH底液测定废水中微量铜的新方法,该法灵敏度较高,选择性较好,抗干扰强,简便、快速,与8羟基喹啉-铜络合物吸附波法对照,结果满意.     

人工神经网络在沿海区域环境复杂系统预测中的应用

针对复杂系统的非线性特征，分析了应用人工神经网络技术实现可持续发展复杂系统预测的可能性，并以上海市和崇明县为例建立沿海区域预测模型，取得了较好的预测结果，为可持续发展复杂系统的预测研究探索了一种新的可能方法。     

复杂多台阶空心零件复合挤压变形的控制

在为用挤压工艺生产快门壳而进行的工艺试验中,为了控制这种复杂多台阶空心零件复合挤压正、反挤方向的变形量,采用了改变润滑条件和凹模圆角的工艺措施,得到了预期的效果.从而为确定类似空心零件挤压生产工艺参数提供了一种简便而行之有效的方法.     

ENERGY LOSS AND REPLACEMENT COST OF NAVIGATION OF THE SNAKE-COLUMBIA RIVERS1

ABSTRACT: A competitive relationship exists between power production and navigation in the allocation of water resources along the Snake-Columbia River Complex. This report identifies the energy losses within the power system and the replacement costs of water diversion which resulted from commercial and recreational navigation of the Complex over the period 1975–1977.     

壳聚糖/碱铝复配絮凝剂在炼油污水处理中的应用

研究了壳聚糖(CHI)／碱铝(PAC)复配絮凝剂对炼油污水的处理效果，考察了pH值、搅拌时间、沉降时间对炼油污水处理效果的影响，并将之与聚丙烯酰胺(GD-112)／PAC复配絮凝剂对炼油污水处理的效果进行对比。结果表明，CHI／PAC复配絮凝剂在复配比为1：5，pH为7，搅拌10min且沉降10min时处理效果最好，具有适应性广、投加量少、浮渣少、毒性低等特点。